﻿using System;

namespace Demo4.ExtendDemo
{
    /// <summary>
    /// 扩展方法demo
    /// </summary>
    public class Main
    {
        private Main()
        {
            string s = null;
            if (s.IsNullOrBlank())
            {
                Console.WriteLine("空");
            }
        }

        public static Main NewInstance()
        {
            return new Main();
        }
    }
}